Air brake mechanism for street oars



(No Model.)

3 Sheets-Sheet l.

GQA. GLASS.

AIR BRAKE MEGHANISM POR STREET GARS.

vPatented Oct. 2Q, 1896.

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No. 569,915. PatentedOot. 20, 1896.

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G. A. GLASS. AIB. BRAKE MECHANISM FOR STREET GARS.

No. 569,915. Patented Oct. 20, 1896. i'

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, vUNITED STATES GEORGE ALLEN GLAss, or EREEBURG, PENNsYLvANmAssIGNoE oE-frwo- PATENT EEICEl g THIRDS T0 P. J. BICKLE AND D. G. SMITH, OF SAME PLACE.

AIR-,BRAKE MECHANISM FOR STREET-CARS.

SPECIFICATION forming part of Letters Patent No. 569,915, dated October 20, 1896.

Application lled April 30, 1896. Serial No. 589,694. (No model-l To all whom t may concern,.-

Beit known that I, GEORGE ALLEN GLASS, a citizen of the United States, residing at Freeburg, in the county of Snyder and State of Pennsylvania, have invented a new and 'useful Air-Brake Mechanism for Street-Cars, of which the following is a specification.

My invention relates to car-brake mechan-V ism particularly adapted for use in connection with street-car service, and the object in View is to provide a simple and improved construction adapted for use in connection with street-cars whereby the brakes may be applied by utilizing the momentum of the car and whereby, when not required, energy is not expended in compressing air.

Further objects and advantages of this invention will appear in the following description, and the novel features thereof will be particularly pointed out in the appended claims.

In the drawings, Figure 1 is a side view, partly in section, of a brake mechanism embodying my invention applied in the operative position to a street-car. Fig. 2 is a bottom plan view of the same, partly in section. Fig. 3 is a detail View of the controlling-valve and contiguous parts. Fig. 4 is a transverse section of brake and pump cylinders arranged in compact and preferable relative positions, the same being formed in a single casting. Fig. 5 is a longitudinal section of the same on the plane indicated by the line 5 5 of Fig. 4, said section being taken centrally through the brake-cylinder and one of the pump-cylinders.

Similar numerals of reference indicate corresponding parts in all the figures of the drawings.

l designates a brake-cylinder in which operates a piston 2, having a rod 3 connected to one end of a brake-lever 4, and. connected with this brake-lever by any suitable means, such as brake-rods 5, are brake-bars 6, carrying brake-shoes 7.

Arranged in communication with one endof the brake-cylinder by means of a suitable conductor 8, having branches 9, are pumpcylinders 10, of which any desired number may be employed. In the construction illustrated twin pump-cylinders are arranged in communication with a common conductor 8.

The pump pistons or plun gers 11 have their stems or rods l2 operatively connected with one of the wheel-axles 13 by such means as. 55 will cause a reciprocatory movement in opposite directions of the pistons, and in the construction illustrated said means consist ofcranks 14 on the axle and pitmen l5, connecting the cranks with said stems or rods 12. 6o

The pump-cylinders are provided with inlet -openings fitted with inwardlyopening check-valves 16, and similar outwardly-opening check-valves 17 are arranged at the outletports, which communicate with the branches of the conductor 8. An inwardly-opening checkvalve 18 is arranged at the discharge end of said conductor to allow air to pass into the brake-cylinder and prevent the return thereof. Furthermore, the brake-cylinder is 7o provided with an 'exhaust-port 19, fitted with a controlling-valve 2O of any suitable construction, connected by means of rods 2l with operating devices 22, located contiguous to the dash at one or both ends of the car. In the drawings said operating means consist of rock-shafts .provided at their lower extremities with crank-arms 23, to which the rods 2l. are connected.

It will be understood that the pump-pistons 8o are continuously operated during the movement of the car; but as long as the controlling-valve 2O is left open the air forced through the conductor 8 will escape freely and will not affect the' brake-piston. When it is de- 8 5 sired to apply the brakes, the controlling- Valve is manipulated to close the exhaustport, whereupon the air compressed in the brake-cylinder actuates the piston 2 and thus communicates motion to the brake lever. 9o Therelease of the brakes is accomplished by opening the controlling-valve.

In practice I prefer to so proportion the ca- V pacities of the pump and brake cylinders that one revolution of the wheels of the car will charge the brake-cylinder and thus set the brakes; but it may be varied, as found necessary, to suit diderent conditions under which itis necessary to operate the mechanism. Ioo

In the construction illustrated the controlling-valve 2O consists of a slide fitted in a suitable valve-casing 24A, communicating with the exhaust-port, and hence only a slight movement of the operating devices is required toeither open or close the exhaust-port 19.

In Figs. 4 and 5 I have shown a preferable relative arrangement of the brake and pump cylinders wherein said cylinders are formed in a single casting, with the pump-cylinders 25 disposed side by side beneath the brakecylinder 2G and a conductor 2T cored in the space between said cylinders. The arrangement of the valves and the operation of the parts are the same as hereinbefore described, the advantage of this arrangement residing in its compactness and simplicity and the cheapness of its manufacture.

Various changes in the form, proportion, and the minor details of construction may be resorted to without departing from the spirit or sacrificing any of the advantages of this invention.

Having described my invention, what I claim is l. Air-brake mechanism having a brakecylinder, twin pumps in communication with the brake-cylinder at one end, means for continuously operating the pump-pistons during the movement of the vehicle, and valve mechanism controlling an exhaust port in the brake-cylinder, and including an open-ended guide or easing covering said port, and a slide-valve operating in the guide or casing, substantially as specified.

2. Air-brake mechanism having brake and pump cylinders `formed in a common casting with an intermediate cored passage in communication by valved ports with said cylinders, pistons mounted in the pump-cylinders and adapted to be continuously operated during the movement of the vehicle, a brakepiston, and a valve controlling` an outlet-port in communication With the brake-cylinder, substantially as specified.

3. Air-brake mechanism having parallel brake and pump cylinders connected by an interposed parallel conductor, said conductor having valved communication with the cylinders, pistons mounted in said cylinders, the pump-cylinder pistons being adapted to be continuously operated during the movement of the vehicle, and a controlling-valve for an exhaust port in communication with the brake-cylinder, said valve being mounted for movement parallel With the axis of the cylinder and having a stem connected to a handlever, substantially as speciiied.

In testimony that I claim the foregoing as my oWn I have hereto afiixed my signature in the presence of two Witnesses.

FRANK N. BECKMAN, L. J. BOYER. 

